In the field of vessels for transporting liquidated gas, there are primarily two known techniques, that is, on the one hand, hermetically sealed vessels equipped with a system enabling the internal pressure to be controlled and, on the other hand, non-hermetic vessels to which the invention particularly relates. These non-hermetic vessels are used for the transport and/or storage of liquefied gas under atmospheric pressure, these vessels being equipped to allow the free escape of vapors with a density greater than air that are produced progressively with the reheating of the liquefied gas.
For example, a cryogenic fluid such as liquid nitrogen can be transported in a thermally insulated vessel, also called a cryostat, devoid of a system ensuring the imperviousness of the closure. However, the vessel must in return be kept in a vertical position in order to avoid accidental spillage of the liquid nitrogen. This type of vessel is, for example, very widely used for transporting biological materials requiring conservation at a very low temperature. Thus, the majority of known vessels used as a transportation device are cryostats comprising an insulting bulb consisting of two metal walls separated by the void and connected by a ring ensuring the connection between the free upper ends of each of the walls, in the area of the neck of the bulb. In these vessels, the outside metal wall of the insulating bulb thus directly constitutes the outside packing of the transportation device, which can, however, have an additional packaging structure within which is the metal cryostat.
One immediately realizes that the use of metal materials to manufacture such cryostats entails a high manufacturing cost that consequently precludes any single-use utilization. Then, for transporting products whose commercial value is sometimes low, the shipment expenses generated by the use of such cryostats as transportation devices are very significant. On the one hand, the weight of the metal cryostat contributes to increasing the cost of the transport and, on the other hand, the empty repatriation of the vessel to the original place of shipment must be organized because the expenses incurred for returning it are usually less than the purchase price of a new unit.
This consignment system is a significant constraint, particularly when it involves far-away shipments by air or when the shipper must meet strong sporadic seasonal demands subject to the biological laws, which are difficult to circumvent. This is particularly the case for the reproduction of certain animal species from frozen gametes or embryos.
Furthermore, these metal cryostats are often not very stable because they exhibit a bottom with a relatively reduced section, compared to their height. The height of the cryostats is particularly determined in relation to the pipes bearing the products that are destined to be vertically introduced in the internal volume of the vessel and that facilitate transfers between vessels.
Finally, despite the use of metal materials, the transportation devices made up of such cryostats remain particularly vulnerable to shock(s) and to falling during transport, with increased risk of deterioration due to their lack of stability. In fact, in the event of shock(s) or fall(s), the forces are, particularly in the absence of a packaging structure, directly received by the outer wall of the insulating bulb and transmitted to the ring ensuring the connection with the inner wall. Such forces often cause the connecting ring to rupture, and such a rupture of the ring laid out in the area of the neck of the bulb is fatal to the transported products because the vacuum between the walls is lost; the bulb then loses its insulation properties, no longer ensuring its conservation at low temperature. What is more, to these outside forces, stemming from the shocks or the falls sustained by the cryostat, are added other forces in the opposite direction that are transmitted to the inner wall by the content of the bulb, particularly the cryogenic fluid, such as liquid nitrogen. The combining of these forces on the inner and outer walls cause severe damage to the ring, in turn leading to the total or partial loss of the cooling cryogenic liquid due to evaporation and inevitably resulting in the loss of the transported or stored product. The resistance of the ring, which is generally made of a composite or analogous material to prevent a thermal bridge from forming, is not sufficient to sustain such forces, particularly torsion. That is the reason why numerous ruptures are noted in the area of the connecting ring that constitutes the only contact point or area between the inner and outer walls of the double wall of the bulb.
One possible solution is to pack the cryostat in a packaging structure in such a way as to try to protect it at least from direct shock(s); however, such a solution also contributes to increasing both the manufacturing and usage costs of such cryostats, and the total transported weight. Furthermore, the risk of severely damaging the connecting ring is not eliminated despite this and persists particularly in case of a severe shock or a fall because the resulting forces are directly transmitted by the packaging structure to the metal outer wall of the cryostat.
Such transportation devices or metal cryostats are thus not entirely satisfactory, particularly given their manufacturing and usage costs, their vulnerability to shock(s) and to fall(s) likely to occur during transport and also preclude a single use. The invention proposes a new design for a transportation and/or storage device making it possible to specifically remedy the abovementioned shortcomings of the state of the art.
To this end, the invention proposes a device for transporting and/or storing products, particularly of cryostat type, having an external packaging structure comprising walls defining an internal volume within which is a double-walled insulating bulb whose body is formed by an outer wall and an inner wall defining an internal volume, the bulb comprising an upper neck defining an upper filling opening, the device comprising bulb supporting means that comprise attachment means capable of engaging with the only inner wall of the bulb in order to vertically suspend the bulb by its neck in such a way that the bulb hangs freely in the empty space inside the internal volume defined by the packaging structure, with no contact between the outer wall of the bulb and the walls of the packaging structure, said device being characterized in that the means for the suspended support of the bulb consist of at least one of the walls of the packaging.